Helium, English name Helium, symbol He, colorless and odorless, non-flammable gas, the content of air is about 5.2 parts per million. Chemically inactive, usually not combined with other elements or compounds. On July 10, 1908, Dutch physicist Onis first liquefied helium.
Helium is one of the rare strategic materials indispensable for the development of defense military industry and high-tech industries. Helium-containing natural gas is still the only source of helium for industrial production. China’s helium resources are quite scarce, the content is very low, the extraction is difficult, and the cost is high. Therefore, while protecting limited helium resources, research and development of advanced natural gas helium extraction technology is of great significance for improving the economics of helium production, ensuring the safety of national helium use, and promoting the development of China’s natural gas helium extraction industry. According to the analysis and introduction of helium extraction technology, the low-temperature condensation method is more mature, but the energy consumption and cost are higher; other helium extraction technologies such as adsorption method, absorption method and membrane permeation method have their own characteristics, but cannot be scaled to the industry due to the applicable conditions. application. With the development of new materials and new technologies, natural gas helium extraction technology has been continuously improved and innovated. Adsorption methods, membrane permeation methods, and other helium extraction technologies have developed rapidly. The combined production method and the combined method process have good application prospects. The development of helium technology provides new ideas.
Helium is widely used in military, scientific research, petrochemical, refrigeration, medical, semiconductor, pipeline leak detection, superconducting experiments, metal manufacturing, deep-sea diving, high-precision welding, and optoelectronic product production.
- Low temperature cold source: Utilizing the low boiling point of -268.9 ℃ of liquid helium, liquid helium can be used for ultra-low temperature cooling. The ultra-low temperature cooling technology has a wide range of applications in superconducting technology and other fields. Superconducting materials need to exhibit superconducting characteristics at low temperatures (about 100K). In most cases, only liquid helium can achieve such extremely low temperatures relatively easily. . Superconducting technology has been widely used in magnetic levitation trains in the transportation industry and MRI equipment in the medical field.
- Balloon inflation: Because the density of helium is much smaller than that of air (the density of air is 1.29kg / m3 and the density of helium is 0.1786kg / m3), and its chemical properties are extremely inert and safer than hydrogen (hydrogen can burn in the air) , May cause an explosion), helium is often used to fill gas in spacecraft or advertising balloons.
- Inspection and analysis: The superconducting magnet of the nuclear magnetic resonance analyzer commonly used in instrument analysis needs to use liquid helium to cool down. Helium is often used as a carrier gas in gas chromatography analysis. It uses the characteristics of good permeability and non-flammability of helium. Used in vacuum leak detection, such as helium mass spectrometer.
- Protective gas: Utilizing the inert chemical properties of helium, helium is often used as a protective gas for welding of metals such as magnesium, zirconium, aluminum, and titanium.
- Other aspects: Helium can be used as a high-vacuum device, nuclear reactor, pressurized gas used to transport liquid hydrogen, liquid oxygen and other liquid propellants on rockets and spacecraft. Helium is also used as a cleaning agent for atomic reactors, in breathing gas mixtures for marine development, and as filling gas for gas thermometers.